Water is increasingly becoming a scarce resource, especially in arid regions of the world, and its efficient utilization is therefore becoming imperative—both economically and in terms of national goals. In buildings—both residential and commercial—a substantial portion of water consumption, estimated at between 30% and 50%, is for flushing toilets. Various means for reducing the amount of water needed for toilet flushing are in general use—notably efficient flushing mechanisms that require a smaller quantity of water per flush and means for selective variable quantity flushing (e.g. dual quantity flush). These, however, are not sufficient and a greater degree of saving is desired.
Generally, all the water currently fed to toilet flushing tanks comes from the main water supply line, which generally is connected to the municipal water supply system. This water is pure enough to serve also for all other purposes, such as washing and drinking. Fortunately, toilet flushing water need not be so pure and therefore alternate sources available in buildings can be contemplated for this purpose. These may include—
(a) condensate water from air-conditioners,
(b) water from water heaters that has cooled in distribution pipes and is normally wasted while waiting for fresh hot water to arrive and
(c) so-called gray water from water re-use systems, utilizing waste water from sinks, bathtubs and showers.
A further source may be collected rain- and snow water. Water from all these sources, and similar ones, is here collectively referred to as excess water.
There may be also other uses in a building for water from alternate sources, such as any of those listed above, to replace water from the main supply. Such uses may include inter alia feeding washing machines and cleaning floors.
Japanese patent JP9280592A discloses apparatus, comprising a storage tank for accumulating collected condensate water from one or more air-conditioners, the storage tank being configured to quickly and automatically refill the tank of a flushing toilet immediately after it has been operated and before any substantial amount of water has been drawn from the main supply. This apparatus has several drawbacks, including (a) that it may feed only one flushing tank, (b) that the amount of water that may be accumulated in the storage tank is equal to that required to fill the flushing tank once only and (c) that the accumulated water cannot be used for any other purpose, such as mentioned above. Furthermore, there is not disclosed means for utilizing water from any of the other alternate sources listed above.
There is thus a need for a system that can accumulate any desirable amount of excess water from one or more alternate sources in a building and deliver any of the accumulated water, as needed, to one or more flushing toilets and possibly also to other water consumption devices—for other uses.